The operation of a mini-hub and multiple remote terminals in a hitless or a non-redundant configuration is described in the parent application. The present invention is concerned with multiple mini-hub satellite earth stations communicating with numerous remote satellite earth stations.
In order to maintain communication in the event of equipment failure, catastrophic events, or a change in a Regional Control Center responsibility for selected remote terminals, it is desirable to develop a mesh mini-hub network topology. This will allow communications to be rerouted to Regional Control Centers without taking down any portion of the operating network.
With prior technology it has not been possible to develop an Ultra Small Aperture Terminal (USAT) or Very Small Aperture Terminal (VSAT) Code Division Multiple Access (CDMA) satellite communications network using spread spectrum encoded signals communicating with discontinuous signals from multiple hubs. This capability is essential to allow multiple mini-hubs to communicate with numerous remote terminals.
In order to maintain communication in the event of equipment failure, redundant equipment is implemented which is normally in a standby mode. It is desirable to eliminate redundant standby equipment for fail safe operation by utilizing the redundant equipment for other functions that can be interrupted prior to assuming the standby role.
Reference frequency oscillators used in communications equipment, experience frequency variations due to changes in ambient environmental temperatures and aging. These variations need to be kept to a minimum and accommodated in the integration of the RF and baseband equipment.
Conventional high gain antennas operating in high frequency bands ranging from C- band to Ka-band frequencies are constructed from wave-guide feedhorns with dish antennas, radiating slots or micro-strip patches, and usually have less bandwidth, than is achievable. The prior art utilized all unbalanced circuitry for transmission/reception and radiation from the array.
The prior art does not disclose the use of passive balanced arrays for fixed or mobile antennas. The prior art uses active arrays that are considerably more expensive than necessary.
The accuracy of prior art power system fault location schemes have been limited by the inability to synchronize sensors separated by hundreds of miles to within 0.3 to 0.5 micro-seconds. The use of series capacitor banks on power transmission lines has made it considerably more difficult for 60-cycle frequency or impedance-based fault location methods to work effectively. Other problems include large fault inspection and clearing times, high ground resistance, lack of visual evidence of a fault in some instances, and problems due to reflections experienced by conventional time domain reflectometors.